There is growing interest in understanding decisions made by potential participants regarding voluntary participation in cancer prevention trials (CPTs). Little is known about consumer reasoning leading to these decisions, particularly on the part of minority groups, such as African-American and Hispanic-American groups, that tend to be underrepresented in such trials. This project will develop and test a valid and reliable instrument to measure the prevalence of positive and negative attitudes of former cancer patients toward cancer trials (CTs) in general and CPTs in particular. It will focus specifically on former cancer patients who, because of their increased risk for future cancer, are likely to be eligible for CPTs. It will also measure group differences in attitudes by cancer site and ethnicity. The project will be divided into three phases. In Phase I, an instrument to measure attitudes toward CTs and CPTs, the Attitudes toward Cancer Trials Scale (ACTS), will be developed and refined through (1) item analysis, (2) assessment of internal consistency reliability and (3) known-groups and factor analysis approaches to evaluate the construct validity. In Phase II a questionnaire comprised of the refined ACTS, sociodemographic variables, and cancer trial enrollment history will be designed and piloted to test mail survey procedures and gather data for test-retest reliability assessment. In Phase III a cross- sectional survey will be conducted. The questionnaire will be mailed to 1,902 cancer patients from M.D. Anderson Cancer Center, Houston, Texas. These patients will have been newly registered for treatment within the past three years and will have presented with an early-stage cancer or a previous, successfully-treated malignant breast, prostate, lung, or colorectal cancer. Differences in attitudes toward CTs and CPTs will be analyzed by site and by sociodemographic groups that are differentially represented in cancer trials. This project is part of an emerging program of research that aims to develop knowledge about consumer decision making in CPT enrollment. Findings will provide an empirical basis for bridging the realities of the clinical trial process with health consumer views of participating in these trials.